XorgCtrlAltBackspace

The Ctrl-Alt-Backspace key combination currently "zaps" (hard-restarts) the X server, and thus loses any unsaved data in applications, etc. This key combination is also largely undocumented, so users (probably ex-Windows users) may press this key combination without expecting data loss. This spec proposes to follow upstream's lead and disable this key combination by default in order to prevent this usability issue from occurring in normal installs.

The key combination of Ctrl-Alt-Backspace, which previously immediately exited X (and thus reset the graphics system back to the login screen), has been changed to disabled by default. It can be re-enabled by setting the DontZap xorg.conf option to False or by using the AltGr-SysReq-K key combination instead. This should help reduce the frequency of unexpected data loss and activity interruption for users unaware of its function that strike it accidentally.

For people coming here because they are missing the nice functionality of being able to kill the X server in case nothing else works anymore in the GUI, it might be interesting to know that x can now be killed with "AltGr" - "SysReq" - K (AltGr is the right Alt key. SysReq also labeled "Print Screen."

On Ubuntu, you can edit you xorg.conf (/etc/X11/xorg.conf) and add the DonZap "False" value. That will make Ctrl + Alt + Backspace work again.

Section "ServerFlags"
      Option          "DontZap"               "false"
EndSection